Safety cranking device for motor-vehicles.



J. P. CARSON.

SAFETY C RANKING DEVICE FOR MOTOR VEHICLES.

APPLICATION FILED JAN.26. [917.

1 ,268Q538 Patented June 4, 1918.

ens earn JOSEPH PRESTON season, or Brent romp, vrnernre, nssrenon Tooartsoiv MANUFAC- TUBING CORPORATION, or RICHMOND, VIRGINIA, Aconronarron or VIRGINIA.

SAFETY CBANKING Dnvron ron MOTOR-VEHICLES.

raeasae.

Specification of Letters Patent.

Patented June 1, 1918.

Original application filed December 23, 1915, Serial No. 68,385. Dividedand this application filed January To all whom it may concern:

Be it known that I, Josnrrr P. CARSON, a citizen of the United States,residing at Richmond, in the county of Chesterfield and State ofVirginia, have invented certain new and useful Improvements in SafetyCranking Devices for Motor-Vehicles; and I do hereby declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains tomake and use the same.

My invention relates to improvements in safety cranking devices forexplosive engines and is a division of my application, Serial No.68,385, filed Dec. 23, 1915.

The invention consists in the novel features hereinafter described,reference being had to the accompanying drawing in which I have showntwo forms or embodiments of my invention selected by me for purposes ofillustration, and the said invention is fully disclosed in the followingdescription and claims.

Referring .to the drawing: Figure 1 is a side view partly in section andpartly broken away, of an ordinary crank provided with my improvedmechanism for throwing the crank away from the engine shaft, when aback-lire or the like occurs in the engine during'the period when theoperator iscranking the engine.

Fig. 2 is a detail showing a face view of a ratchet wheel, which isrigidly secured to the front of a motor vehicle and a pawl member whichis loosely mounted on the crank and cooperates with the teeth of saidwheel.

Fig. 3 is a perspective View of said pawl member.

Fig. 4 is a diagrammatic view showing the method of disconnecting theratchet member from the loose pawl, in case of backfire in the engine.

Fig. 5 is a perspective view of the modified ratchet member, for movingthe loose pawls over the teeth of the other ratchet member.

In cranking up or starting an explosive engine, by means of the ordinaryhand crank, there is great danger of the charge igniting and explodingprematurely, as the piston is approaching the head of the cylinder. Whenthis occurs, the engine, and conse- Seria1 No. 144,696.

backward impetus, and the operators arm or wrist is frequently broken orbadly in jured, by the powerful backward blow of the crank. A number .ofefforts have been made to produce a safety device, which would beeffective for preventing injuries of the character above described, butsuch devices, as hitherto constructed, have not been successful inoperation.

It is. the object of the present invention to obviate thisseriousdefectrelating'to the starting of explosive engines, by providing between theengine shaft and hand crank, mechanism including as one of its elements,loose pawls which will automatically throw the crank out of engagementwith the engine shaft when a back-fire or the like occurs in the enginecylinder or cylinders.

With the foregoing and other objects in view, which will appear as thenature of my improvement is better understood, the invention resides inthe novel combination and arrangement of parts hereinafter described, itbeing understood that changesin the precise details of the constructiondisclosed may be made, without departing from the spirit or scope of theinvention.

Before proceeding with a more detailed description, it may be stated,that I in the form of my improvement herein shownQI employ a crank shaftand crank for the vehicle, of ordinary construction, special means beingemployed for throwing out the crank when the engine shaft reverses,whereby accidents will be prevented. The construction and organizationof the usual parts of the vehicle, to which my improvement may beapplied, do not require alteration or change in any way, since myimprovement is practically in the nature of an attachment, adapted foruse in connection with almost any type of motor vehicle.

In the embodiment of my invention illustrated in Figs. 1 to e inclusive,the reference numeral 1 designates an ordinary engine crank, having atone end the usual clutch member 2 for engaging a similar clutch on theengine shaft and provided at its opposite end with a hand engagingmember (not shown).

Loosely mounted on the crank is a stationary ratchet wheel 3 provided onits rear face with a bracket 4 for rigidly securing the same to thefront of a motor vehicle and the small teeth of the wheel 3 and providedon its opposite. side with a large tooth 11, for a purpose hereinafterdescribed.

Another ratchet wheel 12 is rigidly mounted on the crank forward of thepawl member and is provided 011 its rear face with large teeth 13, whichcooperate with the large teeth 11 of the pawl member. A coil spring 14surrounds the crank and bears against the wheel 12 and pawl member 6 fornormally maintaining said wheel and pawl member apart and formaintaining the small teeth 10 of the pawl member in con tact with theteeth of the ratchet 3.

A casin 15 incloses the operative portions of the safety mechanism andis secured to ther'atchet wheel 3 by means of screws 16.

In assembling the safety mechanism on a crank, the clutch pin 17 iswithdrawn and the clutch removed. Then the casing is slipped onto thecrank from the rear thereof, after which the ratchet 12 is placed on thecrank and secured by suitable fastening -ls. The spring '14 is thenapplied and the pawl member 6 and wheel 3 follow and finally the casingis secured to the Wheel 3 by the screws 16 and the bracket 4 secured tothe vehicle frame in some suitable manner.

The operation of the device is as follows: When it is desired to crankthe engine, the crank 1 is moved longitudinally against the tension ofthe spring 14, until the clutch 2 engages the clutch of the engineshaft, at which time the teeth 13 of the ratchet wheel 12 will bebrought into engagement with the large teeth 11 of the pawl member. Now,when the crank is turned in the usual manner, the pawls 9 will bereadily moved over the surface of the teeth 5 by the teeth 13 of thewheel 12. This will be continued until the, motor has started, when therapid turning of the engine shaft will throw the crank back to itsnormal osition. During the cranking, however, i there hould be abackfire inthe engine and the engine shaft reversed, the small teeth 10of the pawls 9, would immediately lock on the teeth 5 of the wheel3,over which the pawls are traveling,

and the teeth 13 of the wheel 12, with which the pawls are inengagement, would be re leased from said pawls and the inclined faces ofthe adjacent teeth 13, would ride outwardly upon the pawls andautomatically force the wheel 12 away from the pawls and the clutchmember 2 away from the clutch of the engine shaft, in a manner whichwill be apparent to those skilled in the art.

In Fig. 5 I have illustrated a modified form of ratchet member 20, whichmay be used in place of the wheel 12. This member 20 consists of acollar 21, which is secured to the crank by a fastening 22 and carriesradial arms 23, which terminate in triangular shaped lugs 24 having attheir ends flanges 25, the lugs and flanges forming members for engagingthe large teeth 11 of the pawls. This modified device operates in thesame manner as'the wheel 12 but is less expensive and of lighterconstruction.

From the foregoing, it will be seen that I have devised an improvedsafety cranking device which may be appliedto any ordinary crank withoutchanging the construction of the same, and that by making my pawl memberof but two pawls each having a single tooth on its front and rear sides,I obviate the necessity of employing a wheel at this point having teethextending entirely around both sides of the wheel and the expense andmaterial necessary to make such a wheel.

What I claim and desire to secure by Letters Patent is The combinationwith an internal combustion engine andits shaft, of a crank providedwith a detachable clutch for engaging said shaft, a stationary ratchetmember in which said crank turns, teeth provided on the forward face ofsaid ratchet member, a

collar loosely mounted on said crank and provided with radial armsterminating in pawls having small teeth for engagingthe teeth of theratchet member, and a ratchet wheel rigidly mounted on said crank andhaving teeth which are adapted to engage said pawls for moving the sameover the teeth of the ratchet member when the crank i turned in onedirection and ride off of said pawls when the crank is turned in theopposite direction and the pawls lock on said ratchet member.

In testimony whereof Iaflix my signature.

JOSEPH PRESTON CARSON.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

